On Structural, Optical, and Electrical Properties of Chromium Oxide Cr2O3 Thin Film for Applications

Chromium oxide thin films were grown on Al2O3 substrates by ablating a pure Cr2O3 target using a KrF excimer laser. The energy density on the target surface was 1.4 J/cm2 with a pulse repetition of 3 Hz. The thin films were calcinated at 550°C for 1 h. The structural analysis of the grown layer was achieved using FTIR spectroscopy and X-ray diffraction techniques. The XRD analysis shows the formation of Cr2O3 with crystalline size ranging from 35–40 nm, further confirming from the infrared absorption bands. The PLD deposited thin films show a predominance of the higher oxidation states of chromium while the antiferromagnetic Cr2O3 phase is mostly present in films grown in an O2 ambient. The optical and electrical properties were studied using ellipsometry, UV-vis spectroscopy and I–V techniques. The direct band gap and indirect optical band gap were determined and refractive index, extinction coefficient, absorption coefficient and dielectric constant were measured and presented in this paper. The current voltage characteristics are also part of this work.